U.S. patent application number 15/478660 was filed with the patent office on 2017-07-20 for engine.
The applicant listed for this patent is YANMAR CO., LTD.. Invention is credited to Yuki FUJIMOTO, Tomohiro FUKUDA, Atsuhito IWASE, Yasuaki OKU, Tomohiro OTANI.
Application Number | 20170204798 15/478660 |
Document ID | / |
Family ID | 51020543 |
Filed Date | 2017-07-20 |
United States Patent
Application |
20170204798 |
Kind Code |
A1 |
IWASE; Atsuhito ; et
al. |
July 20, 2017 |
ENGINE
Abstract
The objective of the present invention is to provide an engine
with improved startability and stable operation regardless of the
driving environment and usage conditions. The engine is equipped
with a control means, which calculates a standard injection timing
on the basis of the target rotational frequency of the engine and a
standard injection amount, that is, the amount of fuel injected,
and which corrects the standard injection timing using at least one
correction amount. A fuel injection control unit calculates a
cooling water correction amount on the basis of the target
rotational frequency of the engine, the standard injection amount,
and the cooling water temperature, and when the cooling water
temperature is less than a first prescribed temperature the control
unit corrects the standard injection timing using only the cooling
water correction amount.
Inventors: |
IWASE; Atsuhito; (Osaka,
JP) ; OTANI; Tomohiro; (Osaka, JP) ; OKU;
Yasuaki; (Osaka, JP) ; FUJIMOTO; Yuki; (Osaka,
JP) ; FUKUDA; Tomohiro; (Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
YANMAR CO., LTD. |
Osaka |
|
JP |
|
|
Family ID: |
51020543 |
Appl. No.: |
15/478660 |
Filed: |
April 4, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14655532 |
Jun 25, 2015 |
9644567 |
|
|
PCT/JP2013/074322 |
Sep 10, 2013 |
|
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15478660 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02D 2200/021 20130101;
F02D 41/0052 20130101; Y02T 10/47 20130101; Y02T 10/40 20130101;
F02D 2041/0067 20130101; F02D 41/0077 20130101; F02D 41/068
20130101; Y02T 10/44 20130101; F02D 41/0065 20130101; F02D 41/345
20130101; F02D 2200/101 20130101; F02D 41/005 20130101; F02D
2200/0614 20130101; F02D 41/401 20130101; F02D 41/3005 20130101;
F02D 41/0072 20130101; F02D 2200/0618 20130101 |
International
Class: |
F02D 41/00 20060101
F02D041/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 25, 2012 |
JP |
2012-281650 |
Dec 25, 2012 |
JP |
2012-281651 |
Claims
1. An engine comprising: an exhaust gas recirculation (EGR) device
structured to recirculate part of exhaust gas as EGR of the engine
as EGR gas into intake air; an EGR valve structured to limit a
weight of the EGR gas; a differential pressure detector comprising
an intake pressure detecting sensor and an exhaust pressure
detecting sensor, the differential pressure detector being
structured to detect differential pressure between an intake
pressure and an exhaust pressure; a control device configured to
change an opening degree of the EGR valve and adjust the EGR gas
weight, the control device comprising a plurality of effective
passage cross-sectional area maps for calculating the effective
passage cross-sectional area of the EGR device from the opening
degree of the EGR valve and the differential pressure; wherein the
control device is configured to calculate the effective passage
cross-sectional area from one effective passage cross-sectional
area map selected from the plurality of effective passage
cross-sectional area maps.
2. The engine according to claim 1, wherein the control device is
configured to select the one effective passage cross-sectional area
map based on a number of revolutions and an injection amount of the
engine.
3. The engine according to claim 1, wherein the control device is
configured to select the one effective passage cross-sectional area
map based on an intake-and-exhaust pressure ratio between the
intake pressure and the exhaust pressure, and the exhaust pressure.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation application of
U.S. patent application Ser. No. 14/655,532, filed on Jun. 25,
2015, the entire contents of which are incorporated herein by
reference and priority to which is hereby claimed. application Ser.
No. 14/655,532 is the U.S. national stage of Application No.
PCT/JP2013/074322, filed on Sep. 10, 2013. Priority under 35 U.S.C.
.sctn.119(a) and 35 U.S.C. .sctn.365(b) is claimed from Japanese
Application No. 2012-281650, filed Dec. 25, 2012, and Japanese
Application No. 2012-281651, filed Dec. 25, 2012, the disclosures
of which are also incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to an engine and more
particularly relates to an engine that includes a fuel injection
control device.
BACKGROUND ART
[0003] Conventionally, regarding diesel engines, there is a case
where the vaporization of fuel is not facilitated at a cold start,
and startability is reduced. Accordingly, there have been known
fuel injection devices that correct a fuel injection time in such a
manner as to intentionally advance the fuel injection time at the
cold start. When the coolant temperature of the engine is lower
than a predetermined temperature, correction is made in such a
manner as to advance the fuel injection time until the coolant
temperature reaches the predetermined temperature, which improves
the startability of the engine. For example, Patent Literature 1
discloses the above-mentioned engine.
[0004] The fuel injection control device disclosed in Patent
Literature 1 makes correction (advance correction) in which, when
the coolant temperature is equal to or lower than a predetermined
temperature at the start of the engine, an injection time is
advanced. Also, generally, there is a case where the injection time
is advanced and corrected based on an indicator except for the
coolant temperature for the purpose of suppressing the generation
of black smoke and the like. Accordingly, in some operating
environments of the engine, there is a possibility that the
injection time is excessively advanced and corrected not only by
the coolant temperature but also by a plurality of indicators, and
the operating state of the engine becomes unstable, or engine stall
is caused.
CITATION LIST
Patent Literature
[0005] PTL 1: Japanese Unexamined Patent Application Publication
No. 2007-32326
SUMMARY OF INVENTION
Technical Problem
[0006] The present invention has been achieved in view of the
above-mentioned circumstances. It is an object of the present
invention to provide an engine that improves startability and
stabilizes operating states irrespective of operating environments
and use modes.
Solution to Problem
[0007] Regarding the present invention, an engine may be configured
to include a control means that calculates a standard injection
time based on a target number of revolutions and a fuel injection
amount of the engine and corrects the standard injection time, fuel
injection pressure, a fuel injection interval, or the fuel
injection amount based on at least a correction amount, and the
control means is configured to calculate a coolant correction
amount based on the target number of revolutions, the fuel
injection amount, and a coolant temperature of the engine, and when
the coolant temperature is less than a first predetermined
temperature, the control means is configured to correct the
standard injection time, the fuel injection pressure, the fuel
injection interval, or the fuel injection amount only based on the
coolant correction amount.
[0008] Regarding the present invention, when the coolant
temperature is equal to or higher than a second predetermined
temperature, the control means is configured to correct the
standard injection time, the fuel injection pressure, the fuel
injection interval, or the fuel injection amount based on at least
the correction amount except for the coolant correction amount.
[0009] Regarding the present invention, the control means may be
configured to set the first predetermined temperature and the
second predetermined temperature in response to an outside
temperature.
Advantageous Effects of Invention
[0010] As the effects of the present invention, the following
advantageous effects are provided.
[0011] According to one aspect of the present invention, under the
condition in which the coolant temperature Tm is substantially
affected, the correction based on the coolant correction amount Wc
can be preferentially performed. Accordingly, the startability is
improved, and operating states are stabilized irrespective of
operating environments and use modes.
[0012] According to another aspect of the present invention, under
the condition in which the coolant temperature is slightly
affected, the correction based on the coolant correction amount is
not made. Accordingly, the startability is improved, and operating
states are stabilized irrespective of operating environments and
use modes.
[0013] According to another aspect of the present invention,
correction conditions based on the coolant temperature are changed
based on the outside temperature at the start of the engine.
Accordingly, the startability is improved, and operating states are
stabilized irrespective of operating environments and use
modes.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a schematic view illustrating the constitution of
a fuel injection control device according to the present
invention.
[0015] FIG. 2 is a view illustrating a graph representing a
relation of a coolant temperature and a correction amount of an
injection time from the start of an engine.
[0016] FIG. 3 is a view illustrating a flowchart representing the
control mode of correcting the injection time of the first
embodiment of the fuel injection control device according to the
present invention.
[0017] FIG. 4 is a view illustrating a flowchart representing the
control mode of correcting the injection pressure of the first
embodiment of the fuel injection control device according to the
present invention.
[0018] FIG. 5 is a view illustrating a flowchart representing the
control mode of correcting the injection intervals of the first
embodiment of the fuel injection control device according to the
present invention.
[0019] FIG. 6 is a view illustrating a flowchart representing the
control mode of correcting the injection amount of the first
embodiment of the fuel injection control device according to the
present invention.
[0020] FIG. 7 is a view illustrating a flowchart representing the
control mode of correcting the injection time of the second
embodiment of the fuel injection control device according to the
present invention.
[0021] FIG. 8 is a schematic view illustrating the constitution of
the engine according to a third embodiment.
[0022] FIG. 9 is a view illustrating the selective map of the
engine according to the third embodiment.
[0023] FIG. 10 is a view illustrating an effective passage
cross-sectional area of an EGR device under predetermined
conditions of the engine according to the third embodiment.
[0024] FIG. 11 is a view illustrating a flowchart representing the
control mode of calculating the effective passage cross-sectional
area of the EGR device of the third embodiment of the engine.
[0025] FIG. 12 is a view illustrating the effective passage
cross-sectional area of the EGR device under each predetermined
condition in a case where the different pressure in the engine is
equal.
[0026] FIG. 13 is a view illustrating the threshold value of the
effective passage cross-sectional area of the EGR device of a
fourth embodiment of the engine.
[0027] FIG. 14 is a view illustrating a flowchart representing the
control mode of calculating the effective passage cross-sectional
area of the EGR device of the fourth embodiment of the engine.
DESCRIPTION OF EMBODIMENTS
[0028] Next, an engine 1 according to a first embodiment of the
present invention will be described referring to FIG. 1.
[0029] As illustrated in FIG. 1, the engine 1 is a diesel engine,
and in the present embodiment, as illustrated in FIG. 1, the engine
1 is an inline four cylinder engine that includes four cylinders
3.
[0030] Regarding the engine 1, outside air supplied via an intake
pipe 2 and fuel supplied from fuel injection valves 4 are mixed in
the interior of cylinders 3 and combusted, thereby drivingly
rotating an output shaft. The engine 1 discharges exhaust gas
generated by the combustion of the fuel to the outside via an
exhaust pipe 5. The engine 1 includes a fuel injection control
device 10 that controls a fuel injection amount injected from the
fuel injection valves 4 and an ECU 18 that controls the engine
1.
[0031] The fuel injection control device 10 serves to control fuel
injection. The fuel injection control device 10 includes an engine
revolution detecting unit 11 that detects the number of revolutions
of the engine 1, an operation amount detecting unit 12 that detects
the operation amount S of an accelerator 7, an atmospheric
pressure/outside temperature detecting unit 13 that detects
atmospheric pressure P and an outside temperature To, an intake
flow amount detecting unit 14 that detects the flow amount of
intake air, a coolant temperature detecting unit 15 that detects a
coolant temperature Tm of the engine 1, a fuel injection pressure
detecting unit 16 that detects fuel injection pressure Fp, and a
fuel injection control unit 17 that is a control means for
controlling the fuel injection.
[0032] The engine revolution detecting unit 11 serves to detect the
number of revolutions N of the engine 1. The engine revolution
detecting unit 11 is constituted by a rotary encoder and provided
on the output shat of the engine 1. It is noted that, in the
present embodiment, the engine revolution detecting unit 11 is
constituted by the rotary encoder, but any may be applied as long
as the number of revolutions N can be detected.
[0033] The operation amount detecting unit 12 serves to detect the
operation amount S of the accelerator 7. The operation amount
detecting unit 12 is constituted by a stroke sensor or an angle
sensor and provided on the output lever of the accelerator 7. It is
noted that, in the present embodiment, the operation amount
detecting unit 12 is constituted by the stroke sensor or the angle
sensor, but any may be applied as long as the operation amount S
can be detected.
[0034] The atmospheric pressure/outside temperature detecting unit
13 serves to detect the atmospheric pressure P and the outside
temperature To. The atmospheric pressure/outside temperature
detecting unit 13 is constituted by an atmospheric pressure sensor,
a temperature sensor, and the like and installed at a position
where the atmospheric pressure P and the outside temperature To can
be measured.
[0035] The intake flow amount detecting unit 14 serves to detect
the intake flow amount F of the engine 1. The intake flow amount
detecting unit 14 is constituted by a flow amount sensor and the
like and installed in the intake pipe 2 of the engine 1.
[0036] The coolant temperature detecting unit 15 serves to detect
the coolant temperature Tm of the engine 1. The coolant temperature
detecting unit 15 is constituted by a temperature sensor and
arranged in a radiator 6 that performs the heat exchange of the
coolant of the engine 1.
[0037] The fuel injection pressure detecting unit 16 serves to
detect the fuel injection pressure Fp of the fuel injection valves
4. The fuel injection pressure detecting unit 16 is constituted by
a pressure sensor and the like and arranged in a fuel pipe, not
illustrated, that supplies the fuel to the fuel injection valves
4.
[0038] The fuel injection control unit 17, which is the control
means, stores various programs for performing the control of fuel
injection, a revolution map M1 for calculating the target number of
revolutions Nt of the engine 1 based on the operation amount S, a
standard fuel injection amount map M2 for calculating a standard
injection amount Qs based on the target number of revolutions Nt
and the coolant temperature Tm, a standard injection time map M3
for calculating a standard injection time ITs of fuel based on the
target number of revolutions Nt and the standard injection amount
Qs, a coolant correction amount map M4 for calculating a standard
coolant correction amount Wcs based on the target number of
revolutions Nt and the standard injection amount Qs, a coolant
temperature correction map M5 for calculating a coolant temperature
correction coefficient Tmf based on the coolant temperature Tm, an
atmospheric pressure correction amount map M6 for calculating a
standard atmospheric pressure correction amount Pcs based on the
target number of revolutions Nt and the standard injection amount
Qs, an atmospheric pressure correction map M7 for calculating an
atmospheric pressure correction coefficient Pf based on the
atmospheric pressure P, a standard injection pressure map M8 for
calculating a standard injection pressure IPs of the fuel based on
the target number of revolutions Nt and the standard injection
amount Qs, a standard injection interval map M9 for calculating a
standard injection interval IIs of the fuel based on the target
number of revolutions Nt and the standard injection amount Qs, a
standard injection amount map M10 for calculating a standard
injection amount IVs of the fuel based on the target number of
revolutions Nt and the standard injection amount Qs, and the
like.
[0039] The target number of revolutions Nt represents the number of
revolutions of the engine 1 rotating at a constant speed in a
no-load state in a case where the accelerator 7 is operated only by
the operation amount S.
[0040] The standard injection amount Qs represents a fuel injection
amount that serves as a standard for the target number of
revolutions Nt at the coolant temperature Tm, in order to suppress
the occurrence of the black smoke from the engine 1.
[0041] The standard injection time ITs represents a fuel injection
time that serves as a standard for the target number of revolutions
Nt and the standard injection amount Qs, which improves the
startability of the engine 1 (prevents the engine stall) and
suppresses the occurrence of the black smoke.
[0042] The standard coolant correction amount Wcs represents a
correction amount that serves as a standard in a case where the
coolant correction is made with respect to the target number of
revolutions Nt and the standard injection amount Qs.
[0043] The coolant temperature correction coefficient Tmf
represents a correction coefficient for calculating a coolant
correction amount Wc at the coolant temperature Tm.
[0044] The standard atmospheric pressure correction amount Pcs
represents a correction amount that serves as a standard in a case
where atmospheric pressure is corrected with respect to the target
number of revolutions Nt and the standard injection amount Qs.
[0045] The atmospheric pressure correction coefficient Pf
represents a correction coefficient for calculating an atmospheric
pressure correction amount Pc at the atmospheric pressure P.
[0046] The standard injection pressure IPs represents fuel
injection pressure that serves as a standard for the target number
of revolutions Nt and the standard injection amount Qs, which
improves the startability of the engine 1 and suppresses the
occurrence of the black smoke.
[0047] The standard injection interval IIs represents a fuel
injection interval that serves as a standard for the target number
of revolutions Nt and the standard injection amount Qs, which
improves the startability of the engine 1 and suppresses the
occurrence of the black smoke.
[0048] The standard injection amount IVs represents a fuel
injection amount that serves as a standard for the target number of
revolutions Nt and the standard injection amount Qs, which improves
the startability of the engine 1 and suppresses the occurrence of
the black smoke.
[0049] A first predetermined temperature Tm1 represents the
threshold value of the coolant in a case where the correction of
the standard injection time ITs is made only based on the
correction for the coolant, in order to improve the startability of
the engine 1 and suppress the occurrence of the black smoke.
[0050] A second predetermined temperature Tm2 represents the
threshold value of the coolant in a case where the correction of
the standard injection time ITs is made based on corrections except
for the correction for the coolant, in order to improve the
startability of the engine 1 and suppress the occurrence of the
black smoke.
[0051] The ECU 18 serves to control the engine 1. In the ECU 18,
various programs and data used for controlling the engine 1 are
stored. The ECU 18 may be configured such that a CPU, a ROM, a RAM,
an HDD, and the like are connected via a bus, or configured to be
made up of one-chip LSI and the like. The ECU 18 includes the fuel
injection control unit 17.
[0052] The fuel injection control unit 17 (ECU 18) is connected to
the fuel injection valves 4 and can control the fuel injection
valves 4.
[0053] The fuel injection control unit 17 is connected to the
engine revolution detecting unit 11 and can acquire the number of
revolutions N detected by the engine revolution detecting unit
11.
[0054] The fuel injection control unit 17 is connected to the
operation amount detecting unit 12 and can acquire the operation
amount S detected by the operation amount detecting unit 12.
[0055] The fuel injection control unit 17 is connected to the
atmospheric pressure/outside temperature detecting unit 13 and can
acquire the atmospheric pressure P and the outside temperature To
detected by the atmospheric pressure/outside temperature detecting
unit 13.
[0056] The fuel injection control unit 17 is connected to the
intake flow amount detecting unit 14 and can acquire the intake
flow amount F detected by the intake flow amount detecting unit
14.
[0057] The fuel injection control unit 17 is connected to the
coolant temperature detecting unit 15 and can acquire the coolant
temperature Tm detected by the coolant temperature detecting unit
15.
[0058] The fuel injection control unit 17 is connected to the fuel
injection pressure detecting unit 16 and can acquire the fuel
injection pressure Fp detected by the fuel injection pressure
detecting unit 16.
[0059] The fuel injection control unit 17 can calculate the target
number of revolutions Nt from the revolution map M1 based on the
operation amount S acquired.
[0060] The fuel injection control unit 17 can calculate an excess
air ratio .lamda. based on the intake flow amount F and the
atmospheric pressure P acquired.
[0061] The fuel injection control unit 17 can calculate the
standard injection amount Qs from the standard fuel injection
amount map M2 based on the coolant temperature Tm acquired and the
target number of revolutions Nt calculated.
[0062] The fuel injection control unit 17 can calculate the
standard injection time ITs from the standard injection time map M3
based on the target number of revolutions Nt and the standard
injection amount Qs calculated.
[0063] The fuel injection control unit 17 can calculate the
standard coolant correction amount Wcs from the coolant correction
amount map M4 based on the target number of revolutions Nt and the
standard injection amount Qs calculated.
[0064] The fuel injection control unit 17 can calculate the coolant
temperature correction coefficient Tmf from the coolant temperature
correction map M5 based on the coolant temperature Tm acquired.
[0065] The fuel injection control unit 17 can calculate the
standard atmospheric pressure correction amount Pcs from the
atmospheric pressure correction amount map M6 based on the target
number of revolutions Nt and the standard injection amount Qs
calculated.
[0066] The fuel injection control unit 17 can calculate the
atmospheric pressure correction coefficient Pf from the atmospheric
pressure correction map M7 based on the atmospheric pressure P
acquired.
[0067] The fuel injection control unit 17 can calculate the
standard injection pressure IPs from the standard injection
pressure map M8 based on the target number of revolutions Nt and
the standard injection amount Qs calculated.
[0068] The fuel injection control unit 17 can calculate the
standard injection interval IIs from the standard injection
interval map M9 based on the target number of revolutions Nt and
the standard injection amount Qs calculated.
[0069] The fuel injection control unit 17 can calculate the
standard injection amount IVs from the standard injection amount
map M10 based on the target number of revolutions Nt and the
standard injection amount Qs calculated.
[0070] The fuel injection control unit 17 can calculate the coolant
correction amount Wc from the standard coolant correction amount
Wcs and the coolant temperature correction coefficient Tmf
calculated.
[0071] The fuel injection control unit 17 can calculate the
atmospheric pressure correction amount Pc from the standard
atmospheric pressure correction amount Pcs and the atmospheric
pressure correction coefficient Pf calculated.
[0072] The fuel injection control unit 17 can advance and correct
the standard injection time ITs, or delay and correct the standard
injection time ITs at an appropriate injection time based on the
coolant correction amount Wc and the atmospheric pressure
correction amount Pc calculated.
[0073] The ECU 18 can control the engine 1 based on the operation
amount S, the number of revolutions N, the target number of
revolutions Nt, the standard injection amount Qs, and the standard
injection time ITs that are acquired via the fuel injection control
unit 17.
[0074] Hereinafter, the control mode of correcting the injection
time of the fuel injection control unit 17 after the start of the
engine 1 according to the first embodiment of the present invention
will be described referring to FIGS. 2 and 3.
[0075] As illustrated in FIG. 2, the fuel injection control unit 17
controls in such a manner that the standard injection time ITs (see
a line B in FIG. 2) is advanced and corrected based on the coolant
correction amount Wc until the coolant temperature Tm (see a line A
in FIG. 2) reaches the first predetermined temperature Tm1 after
the start of the engine 1. Also, the fuel injection control unit 17
controls in such a manner that the standard injection time ITs is
advanced and corrected based on the coolant correction amount Wc
and the atmospheric pressure correction amount Pc until the coolant
temperature Tm, which has reached the first predetermined
temperature Tm1 after the start of the engine 1, reaches the second
predetermined temperature Tm2. Then, when the coolant temperature
Tm reaches the second predetermined temperature Tm2 after the start
of the engine 1, the fuel injection control unit 17 controls in
such a manner that the standard injection time ITs is advanced and
corrected based on the atmospheric pressure correction amount Pc.
It is noted that, in the present embodiment, the correction amount
except for the coolant correction amount Wc is represented as the
atmospheric pressure correction amount Pc, but not limited to
this.
[0076] Next, the control mode of correcting the injection time of
the fuel injection control unit 17 will be specifically described
referring to FIG. 3.
[0077] As illustrated in FIG. 3, after the start of the engine 1,
at Step S110, the fuel injection control unit 17 of the fuel
injection control device 10 acquires the operation amount S
detected by the operation amount detecting unit 12, the atmospheric
pressure P and the outside temperature To detected by the
atmospheric pressure/outside temperature detecting unit 13, the
intake flow amount F detected by the intake flow amount detecting
unit 14, and the coolant temperature Tm detected by the coolant
temperature detecting unit 15 and allows the Step to transfer to
Step S120.
[0078] At the Step S120, the fuel injection control unit 17
calculates the target number of revolutions Nt from the revolution
map M1 based on the operation amount S acquired, calculates the
standard injection amount Qs from the standard fuel injection
amount map M2 based on the coolant temperature Tm acquired and the
target number of revolutions Nt calculated, and allows the Step to
transfer to Step S130.
[0079] At the Step S130, the fuel injection control unit 17
calculates the standard injection time ITs from the standard
injection time map M3 based on the target number of revolutions Nt
and the standard injection amount Qs calculated, and allows the
Step to transfer to Step S140.
[0080] At the Step S140, the fuel injection control unit 17
calculates the standard coolant correction amount Wcs from the
coolant correction amount map M4 based on the target number of
revolutions Nt and the standard injection amount Qs calculated,
calculates the coolant temperature correction coefficient Tmf from
the coolant temperature correction map M5 based on the coolant
temperature Tm, and allows the Step to transfer to Step S150.
[0081] At the Step S150, the fuel injection control unit 17
calculates the standard atmospheric pressure correction amount Pcs
from the atmospheric pressure correction amount map M6 based on the
target number of revolutions Nt and the standard injection amount
Qs calculated, calculates the atmospheric pressure correction
coefficient Pf from the atmospheric pressure correction map M7
based on the atmospheric pressure P acquired, and allows the Step
to transfer to Step S160.
[0082] At the Step S160, the fuel injection control unit 17
calculates the coolant correction amount Wc based on the standard
coolant correction amount Wcs and the coolant temperature
correction coefficient Tmf calculated, calculates the atmospheric
pressure correction amount Pc based on the standard atmospheric
pressure correction amount Pcs and the atmospheric pressure
correction coefficient Pf calculated, and allows the Step to
transfer to Step S170.
[0083] At the Step S170, the fuel injection control unit 17
determines whether or not the coolant temperature Tm acquired is
equal to or higher than the first predetermined temperature Tm1. As
a result, when it is determined that the coolant temperature Tm
acquired is equal to or higher than the first predetermined
temperature Tm1, the fuel injection control unit 17 allows the Step
to transfer to Step S180. In contrast, when it is determined that
the coolant temperature Tm acquired is less than the first
predetermined temperature Tm1, the fuel injection control unit 17
allows the Step to transfer to Step S280.
[0084] At the Step S180, the fuel injection control unit 17
determines whether or not the coolant temperature Tm acquired is
equal to or higher than the second predetermined temperature Tm2.
As a result, when it is determined that the coolant temperature Tm
acquired is equal to or higher than the second predetermined
temperature Tm2, the fuel injection control unit 17 allows the Step
to transfer to Step S190. In contrast, when it is determined that
the coolant temperature Tm acquired is less than the second
predetermined temperature Tm2, the fuel injection control unit 17
allows the Step to transfer to Step S390.
[0085] At the Step S190, the fuel injection control unit 17
corrects the standard injection time ITs calculated based on the
atmospheric pressure correction amount Pc calculated and returns
the Step to the Step S110. That is, the fuel injection control unit
17 does not use the coolant correction amount Wc for the correction
of the standard injection time ITs.
[0086] At the Step S280, the fuel injection control unit 17
corrects the standard injection time ITs calculated based on the
coolant correction amount Wc and returns the Step to the Step S110.
That is, the fuel injection control unit 17 does not use the
atmospheric pressure correction amount Pc for the correction of the
standard injection time ITs.
[0087] At the Step S390, the fuel injection control unit 17
corrects the standard injection time ITs calculated based on the
coolant correction amount Wc and the atmospheric pressure
correction amount Pc and returns the Step to the Step S110.
[0088] In this manner, regarding the engine 1, when the coolant
temperature Tm is less than the first predetermined temperature
Tm1, at which the temperature is substantially affected by the
startability of the engine 1 or the occurrence of the black smoke,
the correction of the standard injection time ITs is made only
based on the coolant correction amount Wc. As a result, the
injection time is not excessively advanced and corrected due to the
addition of the coolant correction amount Wc and the atmospheric
pressure correction amount Pc.
[0089] Also, regarding the engine 1, when the coolant temperature
Tm is equal to or higher than the first predetermined temperature
Tm1 at which the temperature is substantially affected by the
startability of the engine 1 or the occurrence of the black smoke,
and less than the second predetermined temperature Tm2 at which the
atmospheric pressure is substantially affected by the startability
of the engine 1 or the occurrence of the black smoke, the
correction of the standard injection time ITs is made based on the
coolant correction amount Wc and the atmospheric pressure
correction amount Pc. As a result, the injection time is
appropriately advanced and corrected based on the coolant
correction amount Wc and the atmospheric pressure correction amount
Pc.
[0090] Also, regarding the engine 1, when the coolant temperature
Tm is equal to or higher than the second predetermined temperature
Tm2, at which the atmospheric pressure is substantially affected by
the startability of the engine 1 or the occurrence of the black
smoke, the correction of the standard injection time ITs is made
based on the atmospheric pressure correction amount Pc. As a
result, the injection time is not excessively advanced and
corrected due to the addition of the coolant correction amount Wc
and the atmospheric pressure correction amount Pc. In the present
embodiment, when the coolant temperature Tm is equal to or higher
than the second predetermined temperature Tm2, the correction of
the standard injection time ITs is made based on the atmospheric
pressure correction amount Pc, but not limited to this. At least a
correction amount (for example, an outside air temperature, a
lubricant temperature, and an elapsed time from the start of the
engine 1) except for the atmospheric pressure correction amount Pc
may be applied.
[0091] Hereinafter, the control mode of correcting the injection
pressure of the fuel injection control unit 17 after the start of
the engine 1 according to the first embodiment of the present
invention will be described referring to FIG. 4. It is noted that,
in the embodiment described below, regarding the same matters of
the embodiments that have been already described, their specific
descriptions are omitted, and the following description focuses on
the different matters.
[0092] The same control described above is performed from the Steps
S110 to S120.
[0093] At Step S131, the fuel injection control unit 17 calculates
the standard injection pressure IPs from the standard injection
pressure map M8 based on the target number of revolutions Nt and
the standard injection amount Qs calculated and allows the Step to
transfer to the Step S140.
[0094] The same control described above is performed from the Steps
S140 to S180.
[0095] At Step S191, the fuel injection control unit 17 corrects
the standard injection pressure IPs calculated, based on the
atmospheric pressure correction amount Pc calculated and returns
the Step to the Step S110. That is, the fuel injection control unit
17 does not use the coolant correction amount Wc for the correction
of the standard injection pressure IPs.
[0096] At Step S281, the fuel injection control unit 17 corrects
the standard injection pressure IPs calculated, based on the
coolant correction amount Wc and returns the Step to the Step S110.
That is, the fuel injection control unit 17 does not use the
atmospheric pressure correction amount Pc for the correction of the
standard injection pressure IPs.
[0097] At Step S391, the fuel injection control unit 17 corrects
the standard injection pressure IPs calculated, based on the
coolant correction amount Wc and the atmospheric pressure
correction amount Pc and returns the Step to the Step S110.
[0098] Hereinafter, the control mode of correcting the injection
intervals of the fuel injection control unit 17 after the start of
the engine 1 according to the first embodiment of the present
invention will be described referring to FIG. 5. It is noted that,
in the embodiment described below, regarding the same matters of
the embodiments that have been already described, their specific
descriptions are omitted, and the following description focuses on
the different matters.
[0099] The same control described above is performed from the Steps
S110 to S120.
[0100] At Step S132, the fuel injection control unit 17 calculates
the standard injection interval IIs from the standard injection
interval map M9 based on the target number of revolutions Nt and
the standard injection amount Qs calculated and allows the Step to
transfer to the Step S140.
[0101] The same control described above is performed from the Steps
S140 to S180.
[0102] At Step S192, the fuel injection control unit 17 corrects
the standard injection interval IIs calculated, based on the
atmospheric pressure correction amount Pc calculated and returns
the Step to the Step S110. That is, the fuel injection control unit
17 does not use the coolant correction amount Wc for the correction
of the standard injection interval IIs.
[0103] At Step S282, the fuel injection control unit 17 corrects
the standard injection interval IIs calculated, based on the
coolant correction amount Wc and returns the Step to the Step S110.
That is, the fuel injection control unit 17 does not use the
atmospheric pressure correction amount Pc for the correction of the
standard injection interval IIs.
[0104] At Step S392, the fuel injection control unit 17 corrects
the standard injection interval IIs calculated, based on the
coolant correction amount Wc and the atmospheric pressure
correction amount Pc and returns the Step to the Step S110.
[0105] Hereinafter, the control mode of correcting the injection
amount of the fuel injection control unit 17 after the start of the
engine 1 according to the first embodiment of the present invention
will be described referring to FIG. 6. It is noted that, in the
embodiment described below, regarding the same matters of the
embodiments that have been already described, their specific
descriptions are omitted, and the following description focuses on
the different matters.
[0106] The same control described above is performed from the Steps
S110 to S120.
[0107] At the Step S133, the fuel injection control unit 17
calculates the standard injection amount IVs from the standard
injection amount map M10 based on the target number of revolutions
Nt and the standard injection amount Qs calculated and allows the
Step to transfer to the Step S140.
[0108] The same control described above is performed from the Steps
S140 to S180.
[0109] At the Step S193, the fuel injection control unit 17
corrects the standard injection amount IVs calculated, based on the
atmospheric pressure correction amount Pc calculated and returns
the Step to the Step S110. That is, the fuel injection control unit
17 does not use the coolant correction amount Wc for the correction
of the standard injection amount IVs.
[0110] At the Step S283, the fuel injection control unit 17
corrects the standard injection amount IVs calculated, based on the
coolant correction amount Wc and returns the Step to the Step S110.
That is, the fuel injection control unit 17 does not use the
atmospheric pressure correction amount Pc for the correction of the
standard injection amount IVs.
[0111] At the Step S393, the fuel injection control unit 17
corrects the standard injection amount IVs calculated, based on the
coolant correction amount Wc and the atmospheric pressure
correction amount Pc and returns the Step to the Step S110.
[0112] As described above, the engine 1 according to the first
embodiment of the present invention includes the fuel injection
control device 10 including the fuel injection control unit 17,
which is the control means that calculates the standard injection
time ITs based on the target number of revolutions Nt of the engine
1 and the standard injection amount Qs, which is the fuel injection
amount, and that corrects the standard injection time ITs, the
standard injection pressure IPs, the standard injection interval
IIs, or the standard injection amount IVs based on at least a
correction amount, and the fuel injection control unit 17
calculates the coolant correction amount Wc based on the target
number of revolutions Nt, the standard injection amount Qs, and the
coolant temperature Tm of the engine 1, and when the coolant
temperature Tm is less than the first predetermined temperature
Tm1, the fuel injection control unit 17 corrects the standard
injection time ITs, the standard injection pressure IPs, the
standard injection interval IIs, or the standard injection amount
IVs only based on the coolant correction amount Wc.
[0113] With this constitution, under the condition in which the
coolant temperature Tm is substantially affected, the correction
based on the coolant correction amount Wc can be preferentially
performed. Accordingly, the startability is improved, and operating
states are stabilized irrespective of operating environments and
use modes.
[0114] Also, when the coolant temperature Tm is equal to or higher
than the second predetermined temperature Tm2, the fuel injection
control unit 17 corrects the standard injection time ITs based on
the atmospheric pressure correction amount Pc, which is one of
correction coefficients except for the coolant correction amount
Wc.
[0115] With this constitution, under the condition in which the
coolant temperature Tm is slightly affected, the correction based
on the coolant correction amount Wc is not made. Accordingly, the
startability is improved, and operating states are stabilized
irrespective of operating environments and use modes.
[0116] Next, the engine 1 of a second embodiment of the engine
according to the present invention will be described referring to
FIGS. 1 and 7. The engine 1 includes a fuel injection control
device 19. The fuel injection control device 19 includes a fuel
injection control unit 20 and calculates the first predetermined
temperature Tm1 and the second predetermined temperature Tm2 in
accordance with the outside temperature To. It is noted that the
standard injection time will be described in the following
embodiment, out of control modes of the standard injection time,
the fuel injection pressure, the fuel injection interval, or the
fuel injection amount of the fuel injection control unit 17. It is
noted that, regarding the same matters of the embodiments that have
been already described, their specific descriptions are omitted,
and the following description focuses on the different matters.
[0117] As illustrated in FIG. 1, the fuel injection control unit 20
stores a predetermined temperature calculating map M11 for
calculating the first predetermined temperature Tm1 and the second
predetermined temperature Tm2 from the outside temperature To. The
fuel injection control unit 20 performs a predetermined calculation
in accordance with these programs and the like and stores the
results of the calculation.
[0118] The fuel injection control unit 20 can calculate the first
predetermined temperature Tm1 and the second predetermined
temperature Tm2 from the predetermined temperature calculating map
M11 based on the outside temperature To acquired.
[0119] Hereinafter, the mode of fuel injection control after the
start of the engine 1 of the fuel injection control device 19
according to the second embodiment of the present invention will be
described referring to FIG. 7.
[0120] As illustrated in FIG. 7, at Step S135, the fuel injection
control unit 20 calculates the first predetermined temperature Tm1
and the second predetermined temperature Tm2 from the predetermined
temperature calculating map M11 based on the outside temperature To
acquired and allows the Step to transfer to the Step S140. It is
noted that, in the present embodiment, any one of the first
predetermined temperature Tm1 and the second predetermined
temperature Tm2 may be regarded as a calculated value based on the
outside temperature To.
[0121] As described above, regarding the engine 1 according to the
second embodiment of the present invention, the fuel injection
control unit 20, which is a control means, sets the first
predetermined temperature Tm1 and the second predetermined
temperature Tm2 in accordance with the outside temperature To.
[0122] With this constitution, correction conditions based on the
coolant temperature Tm are changed based on the outside temperature
To at the start of the engine 1. Accordingly, the startability is
improved, and operating states are stabilized irrespective of
operating environments and use modes.
[0123] Hereinafter, an engine 21 according to a third embodiment
will be described referring to FIG. 8.
[0124] As illustrated in FIG. 8, the engine 21 is a diesel engine
21, and in the present embodiment, an inline four cylinder engine
21 that includes four cylinders 23.
[0125] Regarding the engine 21, intake air supplied to the interior
of the cylinders 23 via an intake pipe 22 and fuel supplied from
fuel injection valves 24 to the interior of the cylinders 23 are
mixed in the interior of cylinders 23 and combusted, thereby
drivingly rotating an output shaft. The engine 21 discharges
exhaust gas generated by the combustion of the fuel to the outside
via an exhaust pipe 25.
[0126] The engine 21 includes an engine revolution detecting sensor
26, an injection amount detecting sensor 27 of the fuel injection
valves 24, an EGR device 28, and an ECU 35, which is a control
device.
[0127] The engine revolution detecting sensor 26 serves to detects
the number of revolutions N of the engine 21. The engine revolution
detecting sensor 26 is constituted by a sensor and a pulsar and
provided on the output shaft of the engine 21. It is noted that, in
the present embodiment, the engine revolution detecting sensor 26
is constituted by the sensor and the pulsar, but any may be applied
as long as the number of revolutions N can be detected.
[0128] The injection amount detecting sensor 27 serves to detect an
injection amount f of fuel injected from the fuel injection valves
24. The injection amount detecting sensor 27 is provided in a
midway portion of a fuel supply pipe not illustrated. The injection
amount detecting sensor 27 is constituted by a flow amount sensor.
It is noted that, in the present embodiment, the injection amount
detecting sensor 27 is constituted by the flow amount sensor, but
not limited to this, and any may be applied as long as the
injection amount f of fuel can be detected.
[0129] The EGR device 28 recirculates part of the exhaust gas into
the intake air. The EGR device 28 includes an EGR pipe 29, an EGR
valve 30, an intake pressure detecting sensor 31, an exhaust
pressure detecting sensor 32, an EGR gas temperature detecting
sensor 33, an opening degree detecting sensor 34, and an ECU 35,
which is an EGR control unit.
[0130] The EGR pipe 29 is a pipe that guides the exhaust gas to the
intake pipe 22. The EGR pipe 29 is provided in such a manner that
the intake pipe 22 and the exhaust pipe 25 are communicated.
Accordingly, part of the exhaust gas passing through the exhaust
pipe 25 is guided to the intake pipe 22 via the EGR pipe 29. That
is, it is configured such that part of the exhaust gas can be
recirculated into the intake air as the EGR gas (hereinafter,
merely referred to as "EGR gas").
[0131] The EGR valve 30 serves to limit the flow amount of the EGR
gas passing through the EGR pipe 29. The EGR valve 30 is
constituted by the electromagnetic flow control valve of a normal
closed-type. The EGR valve 30 is provided in the midway portion of
the EGR pipe 29. The EGR valve 30 can acquire a signal from the ECU
35 described later and change the opening degrees of the EGR valve
30. It is noted that, in the present embodiment, the EGR valve 30
is constituted by the electromagnetic flow control valve of a
normal closed-type, but any may be applied as long as the flow
amount of the EGR gas can be limited.
[0132] The intake pressure detecting sensor 31 constituting a
differential pressure detecting means serves to detect intake
pressure P1. The intake pressure detecting sensor 31 is provided in
the midway portion of the intake pipe 22 that can detect the intake
pressure P1. Similarly, the exhaust pressure detecting sensor 32
constituting the differential pressure detecting means serves to
detect exhaust pressure P2. The exhaust pressure detecting sensor
32 is provided in the midway portion of the exhaust pipe 25 that
can detect the exhaust pressure P2.
[0133] The EGR gas temperature detecting sensor 33 serves to detect
an EGR gas temperature Tegr. The EGR gas temperature detecting
sensor 33 is constituted by a thermocouple. The EGR gas temperature
detecting sensor 33 is provided in the midway portion of the EGR
pipe 29 that can detect the EGR gas temperature Tegr. It is noted
that, in the present embodiment, the EGR gas temperature detecting
sensor 33 is constituted by the thermocouple, but any may be
applied as long as the EGR gas temperature Tegr can be
detected.
[0134] The opening degree detecting sensor 34 serves to detect an
EGR-valve opening degree G. The opening degree detecting sensor 34
is constituted by a position detecting sensor. The opening degree
detecting sensor 34 is provided in the EGR valve 30. It is noted
that, in the present embodiment, the opening degree detecting
sensor 34 is constituted by the position detecting sensor, but any
may be applied as long as the EGR-valve opening degree G can be
detected.
[0135] The ECU 35 serves to control the engine 21. Specifically,
the ECU 35 controls the main body of the engine 21 and the EGR
device 28. The ECU 35 stores various programs and data used for
performing the control of the engine 21. The ECU 35 may be
configured such that a CPU, a ROM, a RAM, an HDD, and the like are
connected via a bus, or configured to be made up of one-chip LSI
and the like.
[0136] The ECU 35 is connected to the fuel injection valves 24 and
can control the fuel injection valves 24.
[0137] The ECU 35 is connected to the engine revolution detecting
sensor 26 and can acquire the number of revolutions N detected by
the engine revolution detecting sensor 26.
[0138] The ECU 35 is connected to the injection amount detecting
sensor 27 and can acquire the injection amount f detected by the
injection amount detecting sensor 27.
[0139] The ECU 35 is connected to the EGR valve 30 and can control
the opening and closing of the EGR valve 30.
[0140] The ECU 35 is connected to the intake pressure detecting
sensor 31 and the exhaust pressure detecting sensor 32, each of
which is a differential pressure detecting means, and can acquire
the intake pressure P1 detected by the intake pressure detecting
sensor 31 and the exhaust pressure P2 detected by the exhaust
pressure detecting sensor 32 and calculate an EGR differential
pressure .DELTA.P and an intake-and-exhaust pressure ratio
.pi..
[0141] The ECU 35 is connected to the EGR gas temperature detecting
sensor 33 and can acquire the EGR gas temperature Tegr detected by
the EGR gas temperature detecting sensor 33.
[0142] The ECU 35 is connected to the opening degree detecting
sensor 34 and can acquire the EGR-valve opening degree G detected
by the opening degree detecting sensor 34.
[0143] The ECU 35 stores effective passage cross-sectional area
maps R1, R2, . . . Rn (in the present embodiment, effective passage
cross-sectional area maps R1, R2, R3, and R4) for calculating the
effective passage cross-sectional area Ared of the EGR device 28
based on the EGR-valve opening degree G and the EGR differential
pressure .DELTA.P. Also, the ECU 35 stores a selective map Ry for
selecting one effective passage cross-sectional area map Rx out of
the effective passage cross-sectional area maps R1, R2, R3, and R4
based on the number of revolutions N and the injection amount
f.
[0144] The ECU 35 can select one effective passage cross-sectional
area map Rx from the selective map Ry based on the number of
revolutions N and the injection amount f acquired. The ECU 35 can
calculate the effective passage cross-sectional area Ared from one
effective passage cross-sectional area map Rx selected based on the
intake pressure P1, the exhaust pressure P2, the EGR gas
temperature Tegr, and the EGR-valve opening degree G and control
the opening and closing of the EGR valve 30.
[0145] Hereinafter, the control mode of calculating EGR gas weight
Megr in the EGR device 28 of the engine 21 according to the third
embodiment will be described referring to FIGS. 9 to 11.
[0146] The ECU 35 calculates the EGR differential pressure .DELTA.P
represented by Expression 1 below based on the intake pressure P1
and the exhaust pressure P2 acquired and calculates the
intake-and-exhaust pressure ratio .pi. represented by Expression 2
below. Subsequently, as illustrated in FIG. 9, the ECU 35 selects
the effective passage cross-sectional area map Rx from the
selective map Ry based on the number of revolutions N and the
injection amount f acquired. Furthermore, as illustrated in FIG.
10, the ECU 35 calculates the effective passage cross-sectional
area Ared from the effective passage cross-sectional area map Rx
selected based on the EGR differential pressure .DELTA.P calculated
and the EGR-valve opening degree G acquired. Then, the ECU 35
calculates the EGR gas weight Megr represented by Expression 3
below based on the exhaust pressure P2 and the EGR gas temperature
Tegr acquired, the intake-and-exhaust pressure ratio .pi. and the
effective passage cross-sectional area Ared calculated, an exhaust
specific heat ratio .kappa., which is a constant, and a gas
constant R.
.DELTA. P = P 2 - P 1 [ Expression 1 ] .pi. = P 1 / P 2 [
Expression 2 ] Megr = Ared .times. P 2 .times. 2 .times. .kappa. (
.kappa. - 1 ) .times. R .times. Tegr .times. ( .pi. 2 / .kappa. -
.pi. l + 1 / .kappa. ) [ Expression 3 ] ##EQU00001##
[0147] Next, the control mode of calculating the EGR gas weight
Megr in the EGR device 28 of the engine 21 will be specifically
described.
[0148] As illustrated in FIG. 11, at Step S410, the ECU 35 acquires
the number of revolutions N detected by the engine revolution
detecting sensor 26, the injection amount f detected by the
injection amount detecting sensor 27, the EGR-valve opening degree
G detected by the opening degree detecting sensor 34, the intake
pressure P1 detected by the intake pressure detecting sensor 31,
the exhaust pressure P2 detected by the exhaust pressure detecting
sensor 32, and the EGR gas temperature Tegr detected by the EGR gas
temperature detecting sensor 33 and allows the Step to transfer to
Step S420.
[0149] At the Step S420, the ECU 35 calculates the EGR differential
pressure .DELTA.P and the intake-and-exhaust pressure ratio .pi.
from the intake pressure P1 and the exhaust pressure P2 acquired
and allows the Step to transfer to Step S430.
[0150] At the Step S430, the ECU 35 selects one effective passage
cross-sectional area map Rx from the selective map Ry based on the
number of revolutions N and the injection amount f acquired and
allows the Step to transfer to Step S440.
[0151] At the Step S440, the ECU 35 calculates the effective
passage cross-sectional area Ared from the effective passage
cross-sectional area map Rx based on the EGR differential pressure
.DELTA.P calculated and the EGR-valve opening degree G acquired and
allows the Step to transfer to Step S450.
[0152] At the Step S450, the ECU 35 calculates the EGR gas weight
Megr from the intake pressure P2 and the EGR gas temperature Tegr
acquired, the intake-and-exhaust pressure ratio .pi. and the
effective passage cross-sectional area Ared calculated, the exhaust
specific heat ratio .kappa., which is a constant, and the gas
constant R and controls the EGR-valve opening degree G based on the
EGR gas weight Megr calculated. The ECU 35 allows the Step to
transfer to the Step S410.
[0153] That is, as illustrated in FIG. 12, regarding the EGR device
28, when the states of the number of revolutions N and the
injection amount f of the engine 21 are different, there is a case
where, even when the EGR differential pressure .DELTA.P and the
EGR-valve opening degree G are identical, the values of the
effective passage cross-sectional area Ared are different.
Accordingly, the ECU 35 controls in such a manner as to select the
optimal effective passage cross-sectional area map Rx based on the
states of the number of revolutions N and the injection amount f
(see FIG. 9).
[0154] Accordingly, even when the operating states of the engine 21
are different, the EGR gas weight Megr is calculated based on the
EGR differential pressure .DELTA.P and the EGR-valve opening degree
G Consequently, the effect of suppressing the generation of
nitrogen oxide by means of the EGR device 28 is appropriately
given.
[0155] As descried above, regarding the engine 21 according to the
third embodiment, the engine 21 includes the EGR device 28 that
recirculates part of the exhaust gas into the intake air as the EGR
gas, and the engine 21 further includes the EGR valve 30 that
limits the EGR gas weight Megr, the intake pressure detecting
sensor 31 and the exhaust pressure detecting sensor 32 that are a
differential pressure detecting means for detecting differential
pressure between the intake pressure P1 and the exhaust pressure
P2, the ECU 35, which is a control device, that changes the
EGR-valve opening degree G of the EGR valve 30 and adjusts the EGR
gas weight Megr, and the ECU 35 includes the plurality of effective
passage cross-sectional area maps Rx for calculating the effective
passage cross-sectional area Ared of the EGR device 28 from the
EGR-valve opening degree G and the EGR differential pressure
.DELTA.P and calculates the effective passage cross-sectional area
Ared from one effective passage cross-sectional area map Rx
selected from the plurality of effective passage cross-sectional
area maps R1, R2, R3, and R4.
[0156] Also, the ECU 35 selects one effective passage
cross-sectional area map Rx from the plurality of effective passage
cross-sectional area maps R1, R2, R3, and R4 based on the number of
revolutions N and the injection amount f of the engine 21.
[0157] With this constitution, the effective passage
cross-sectional area map Rx in accordance with the operating states
of the engine 21 is selected from among the plurality of effective
passage cross-sectional area maps R1, R2, R3, and R4. Accordingly,
the EGR gas weight Megr based on the operating states can be
calculated.
[0158] Next, the engine 21 of a fourth embodiment of the engine 21
according to the present invention will be described referring to
FIGS. 8, 13, and 14. It is noted that, in the embodiment described
below, regarding the same matters of the embodiments that have been
already described, their specific descriptions are omitted, and the
following description focuses on the different matters.
[0159] As illustrated in FIG. 8, the ECU 35 can select one
effective passage cross-sectional area map Rx, out of the effective
passage cross-sectional area maps R1, R2, . . . Rn (in the present
embodiment, the effective passage cross-sectional area maps R1, R2,
R3, and R4) for calculating the effective passage cross-sectional
area Ared of the EGR device 28 based on the exhaust pressure P2 and
the intake-and-exhaust pressure ratio .pi..
[0160] Hereinafter, the control mode of calculating the EGR gas
weight Megr in the EGR device 28 of the engine 21 according to the
third embodiment will be described.
[0161] As illustrated in FIG. 13, the ECU 35 selects the effective
passage cross-sectional area map Rx suitable for calculating the
effective passage cross-sectional area Ared of the EGR device 28
based on the exhaust pressure P2 acquired and the
intake-and-exhaust pressure ratio .pi. calculated. Specifically,
when the intake-and-exhaust pressure ratio .pi. is higher than a
predetermined value X, and the exhaust pressure P2 is higher than a
predetermined value Y (an area D in FIG. 13), the ECU 35 selects
the effective passage cross-sectional area map R4. Also, when the
intake-and-exhaust pressure ratio .pi. is higher than the
predetermined value X, and the exhaust pressure P2 is equal to or
lower than the predetermined value Y (an area C in FIG. 13), the
ECU 35 selects the effective passage cross-sectional area map R3.
Also, when the intake-and-exhaust pressure ratio .pi. is equal to
or lower than the predetermined value X, and the exhaust pressure
P2 is higher than the predetermined value Y (an area B in FIG. 13),
the ECU 35 selects the effective passage cross-sectional area map
R2. Also, when the intake-and-exhaust pressure ratio .pi. is equal
to or lower than the predetermined value X, and the exhaust
pressure P2 is equal to or lower than the predetermined value Y (an
area A in FIG. 13), the ECU 35 selects the effective passage
cross-sectional area map R1.
[0162] Next, the control mode of calculating the EGR gas weight
Megr in the EGR device 28 of the engine 21 will be specifically
described.
[0163] The ECU 35 performs the same control as the aforementioned
control from the Step S410 to the Step S420.
[0164] At Step S431, the ECU 35 determines whether or not the
intake-and-exhaust pressure ratio .pi. is higher than the
predetermined value X. As a result, when the ECU 35 determines that
the intake-and-exhaust pressure ratio .pi. is higher than the
predetermined value X, the ECU 35 allows the Step to transfer to
Step S432. In contrast, when the ECU 35 determines that the
intake-and-exhaust pressure ratio .pi. is lower than the
predetermined value X, the ECU 35 allows the Step to transfer to
Step S532.
[0165] At the Step S432, the ECU 35 determines whether or not the
exhaust pressure P2 is higher than the predetermined value Y. As a
result, when the ECU 35 determines that the exhaust pressure P2 is
higher than the predetermined value Y, the ECU 35 allows the Step
to transfer to Step S433. In contrast, when the ECU 35 determines
that the exhaust pressure P2 is lower than the predetermined value
Y, the ECU 35 allows the Step to transfer to Step S733.
[0166] At the Step S433, the ECU 35 selects the effective passage
cross-sectional area map R4 and allows the Step to transfer to the
Step S440.
[0167] The ECU 35 performs the same control as the aforementioned
control from the Step S440 to the Step S450.
[0168] At the Step S532, the ECU 35 determines whether or not the
exhaust pressure P2 is higher than the predetermined value Y. As a
result, when the ECU 35 determines that the exhaust pressure P2 is
higher than the predetermined value Y, the ECU 35 allows the Step
to transfer to Step S533. In contrast, when the ECU 35 determines
that the exhaust pressure P2 is lower than the predetermined value
Y, the ECU 35 allows the Step to transfer to Step S633.
[0169] At the step S533, the ECU 35 selects the effective passage
cross-sectional area map R2 and allows the Step to transfer to the
Step S440.
[0170] At the step S633, the ECU 35 selects the effective passage
cross-sectional area map R1 and allows the Step to transfer to the
Step S440.
[0171] At the step S733, the ECU 35 selects the effective passage
cross-sectional area map R3 and allows the Step to transfer to the
Step S440.
[0172] As described above, regarding the engine 21 according to the
fourth embodiment, the ECU 35 selects one effective passage
cross-sectional area map Rx out of the plurality of effective
passage cross-sectional area maps R1, R2, R3, and R4 based on the
intake-and-exhaust pressure ratio .pi. between the intake pressure
P1 and the exhaust pressure P2, and the exhaust pressure P2. With
this constitution, the effective passage cross-sectional area map
Rx in accordance with the operating states of the engine 21 is
selected from among the plurality of effective passage
cross-sectional area maps R1, R2, R3, and R4. Accordingly, the EGR
gas weight Megr based on the operating states can be
calculated.
INDUSTRIAL APPLICABILITY
[0173] The present invention can be utilized for an engine that
includes a fuel injection control device.
REFERENCE SIGNS LIST
[0174] 1 Engine [0175] 10 Fuel injection control device [0176] 16
Fuel injection detecting unit [0177] Nt Target number of
revolutions [0178] P Atmospheric pressure [0179] Tm Coolant
temperature [0180] Qs Standard injection amount [0181] ITs Standard
injection time [0182] Wc Coolant correction amount [0183] Tm1 First
predetermined temperature [0184] 21 Engine [0185] 28 EGR device
[0186] 30 EGR valve [0187] 31 Intake pressure detecting sensor
[0188] 32 Exhaust pressure detecting sensor [0189] 35 ECU [0190]
Megr EGR gas weight [0191] G EGR-valve opening degree [0192]
.DELTA.P EGR differential pressure [0193] Ared Effective passage
cross-sectional area [0194] Rx Effective passage cross-sectional
area map
* * * * *